[Test] public void QuadTree()
{
var qtree = new QuadTree <Watzit>(-10, -5, 20, 10);
// just inside quad0 at the root level
var w0 = new Watzit(-0.5f * qtree.CellSizeX(15), -0.5f * qtree.CellSizeY(15), 0);
var n0 = qtree.Insert(w0, w0.pos, w0.radius);
Assert.Equal(2, qtree.Nodes.Count);
Assert.Equal(15U, n0.m_level);
Assert.Equal(0x4000U - 1, n0.m_x);
Assert.Equal(0x4000U - 1, n0.m_y);
// somewhere in quad3 at the root level
var w1 = new Watzit(2.5f, 2.5f, 0.2f);
var n1 = qtree.Insert(w1, w1.pos, w1.radius);
Assert.Equal(3, qtree.Nodes.Count);
Assert.Equal(4U, n1.m_level);
Assert.Equal(10U, n1.m_x);
Assert.Equal(12U, n1.m_y);
// Outside the region but within the overhang at level 1
var w2 = new Watzit(-14.99f, -7.2499f, 0);
var n2 = qtree.Insert(w2, w2.pos, w2.radius);
Assert.Equal(4, qtree.Nodes.Count);
Assert.Equal(1U, n2.m_level);
Assert.Equal(0U, n2.m_x);
Assert.Equal(0U, n2.m_y);
// Outside the region on y but within on x
var w3 = new Watzit(6.5f, 7.24449f, 0);
var n3 = qtree.Insert(w3, w3.pos, w3.radius);
Assert.Equal(5, qtree.Nodes.Count);
Assert.Equal(1U, n3.m_level);
Assert.Equal(1U, n3.m_x);
Assert.Equal(1U, n3.m_y);
var rand = new Random();
Func <float, float, float> fltc = (avr, d) => rand.FloatC(avr, d);
Func <float, float, float> fltr = (mn, mx) => rand.Float(mn, mx);
for (int i = 0; i != 10000; ++i)
{
var w = new Watzit(fltc(0.0f, qtree.Size.Width), fltc(0.0f, qtree.Size.Height), 0.2f * fltr(0.0f, 0.5f * Math_.Len2(qtree.Size.Width, qtree.Size.Height)));
var n = qtree.Insert(w, w.pos, w.radius);
// the root node can have arbitrarily large objects in it
if (n.m_level != 0)
{
float[] min, max;
qtree.NodeBounds(n, true, out min, out max);
Assert.True(w.pos[0] - w.radius >= min[0]);
Assert.True(w.pos[1] - w.radius >= min[1]);
Assert.True(w.pos[0] + w.radius < max[0]);
Assert.True(w.pos[1] + w.radius < max[1]);
}
}
// Sanity check
int count = 0;
foreach (var node in qtree.Nodes)
{
Assert.True(qtree.SanityCheck(node));
count += node.m_items.Count;
}
Assert.Equal(qtree.Count, count);
for (int i = 0; i != 100; ++i)
{
// reset flags
foreach (var node in qtree.Nodes)
{
foreach (var item in node.m_items)
{
item.flag = false;
}
}
var W = new Watzit(fltc(0.0f, qtree.Size.Width), fltc(0.0f, qtree.Size.Height), 0.2f * fltr(0.0f, 0.5f * Math_.Len2(qtree.Size.Width, qtree.Size.Height)));
qtree.Traverse(W.pos, W.radius, (w, n) =>
{
w.flag = Collide(W, w);
return(true);
});
// All flagged should collide, not flagged should not
foreach (var node in qtree.Nodes)
{
foreach (var item in node.m_items)
{
Assert.Equal(item.flag, Collide(W, item));
}
}
}
}
public static bool Collide(Watzit lhs, Watzit rhs)
{
float[] diff = new[] { rhs.pos[0] - lhs.pos[0], rhs.pos[1] - lhs.pos[1] };
return(Math_.Len2(diff[0], diff[1]) < lhs.radius + rhs.radius);
}
